Detection and identification of Toxocara canis in infected dogs using PCR

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Faecal samples were collected from 224 dogs (47 villages) in Ankara. Toxocara spp. eggs were diagnosed in faeces using centrifugal flotation and sedimentation methods. A total of 21 dogs (9.38 %) were positive for Toxocara spp. eggs. In this study, we used the PCR technique that, in combination with DNA sequencing, allows the detection and identification of T.canis eggs in faeces of infected dogs. For this purpose, the ATPase subunit-6 gene (mtDNA) was selected as a target for the amplification T. canis. The primers were used to amplify 217 bp region. Amongst 21 coproscopically detected Toxocara isolates from dogs, 5 (23.8 %) samples were PCR-positive for T. canis, and the remaining 16 samples were PCR-negative. Results indicate that PCR can detect Toxocara canis DNA in faeces of infected dogs, but efficacy was low when compare to sedimentation/flotation. PCR is additional test for diagnosing of this infection. But, the difficulties of identification based on PCR in faecal examinations need to be investigated further.

AkdeMir, C. (2010): Visceral larva migrans among children in Kütahya (Turkey) and an evaluation of playgrounds for T. canis eggs. Turk. J. Pediatr., 52(2): 158 – 162.

Amaral, H.L.C., RaSSier, G.L., Pepe, M.S., GalliNa, T., Villela, M.M., NoBre, M.o., ScaiNi, C.J., BerNe, M.E.A. (2010): Presence of Toxocara canis eggs on the hair of dogs: A risk factor for Visceral Larva Migrans. Vet. Parasitol., 174(1-2): 115 – 118. DOI: 10.1016/j. vetpar.2010.07. 016

AvcioGlu, H., BurGu, A. (2008): Seasonal prevalence of Toxocara ova in soil samples from public parks in Ankara, Turkey. Vector Borne Zoonotic Dis., 8(3): 345 – 350. DOI: 10.1089/vbz. 2007.0212

Balkaya, İ., Avcioğlu, H. (2011): Gastro-intestinal helminths detected by coprological examination in stray dogs in the Erzurum province-Turkey. Kafkas Univ. Vet. Fak. Derg., 17(Suppl A): S43 – S46.

Borecka, A., Gawor, J., Niedworok, M., Sordyl, B. (2008): Detection of Toxocara canis larvae by PCR in the liver of experimentally infected Mongolian gerbils (Meriones unguiculatus). Helminthologia 45(3): 147 – 149. DOI: 10.2478/s11687-008-0029-9

Bowman, D.D. (2009): Georgis’ Parasitology for Veterinarians. 9th Edition, St Louis-Missouri, USA, Saunders Elsevier

Claerebout, E., Casaert, S., Dalemans, A.C., De Wilde, N., Levecke, B., Vercruysse, J., Geurden, T. (2009): Giardia and other intestinal parasites in different dog populations in Northern Belgium. Vet. Parasitol., 161(1-2): 41 – 46. DOI: 10.1016/j.vetpar.2008.11.024

Çiçek, M., Yilmaz, H. (2012): Prevalence of toxocariasis in human and dogs in Van province. Kafkas Univ. Vet. Fak. Derg., 18(4): 531 – 536. DOI: 10.9775/kvfd.2011.5211

Fahrion, A.S., Schnyder, M., Wichert, B., Deplazes, P. (2011): Toxocara eggs shed by dogs and cats and their molecular and morphometric species-specific identification: Is the finding of T. cati eggs shed by dogs of epidemiological relevance? Vet. Parasitol., 177(1-2): 186 – 189. DOI: 10.1016/j.vetpar.2010.11.028

Felsenstein, J. (1985): Confidence limits on phylogenies: An approach using the bootstrap. Evolution, 39: 783 – 791. DOI: 10.1111/j.1558-5646.1985.tb00420.x

Gasser, R.B. (2013): A perfect time to harness advanced molecular technologies to explore the fundamental biology of Toxocara species. Vet. Parasitol., 193(4): 353 – 364. DOI: 10.1016/j.vetpar. 2012.12.031

Habluetzel, A., Traldi, G., Ruggieri, S., Attili, A.R., Scuppa, P., Marchetti, R., Menghini, G., Esposito, F. (2003): An estimation of Toxocara canis prevalence in dogs, environmental egg contamination and risk of human infection in the Marche region of Italy. Vet. Parasitol., 113(3 – 4): 243 – 252. DOI: 10.1016/S0304-4017(03)00082-7

Jacobs, D.E., Zhu, X., Gasser, R.B., Chilton, N.B. (1997): PCRbased methods for identification of potentially zoonotic ascaridoid parasites of the dog, fox and cat. Acta Trop., 68(2): 191 – 200. DOI: 10.1016/S0001-706X(97)00093-4

Karadam, S.Y., Ertug, S., Ertabaklar, H., Okyay, P. (2008): The comparison of IgG antibodies specific to Toxocara spp. among eosinophilic and non-eosinophilic groups. New Microbiol., 31: 113 – 116

Kimura, M. (1980): A simple method for estimating evolutionary rate of base substitutions through comparative studies of nucleotide sequences. J. Mol. Evolution, 16: 111 – 120

Kozan, E., Gonenc, B., Sarimehmetoglu, O., Aycicek, H. (2005): Prevalence of helminth eggs on raw vegetables used for salads. Food Control 16(3): 239 – 242. DOI: 10.1016/j.foodcont.2004.02.005

Kozan, E., Kircali Sevimli, F., Birdane, F.M. (2007): The occurrence of gastrointestinal cestode and nematode infections in stray dogs in Afyonkarahisar and Eskisehir provinces. Türkiye Parazitol Derg., 31(3): 208 – 211

Kustimur, S., Doğruman Al, F., Oguzulgen, K., Bakir, H., Maral, I., Türktas, H., Tüzün, H. (2007): Toxocara seroprevalence in adults with bronchial asthma. Trans. R. Soc. Trop. Med. Hyg., 101: 270 – 274. DOI: 10.1016/j.trstmh.2006.08.013

Lee, A.C.Y., Schantz, P.M., Kazacos, K.R., Montgomery, S.P., Bowman, D.D. (2010): Epidemiologic and zoonotic aspects of ascarid infections in dogs and cats. Trends Parasitol., 26(4): 155 – 161. DOI: 10.1016/

Li, M.W., Lin, R.Q., Chen, H.H., Sani, R.A., Song, H.Q., Zhu, X.Q. (2007): PCR tools for the verification of the specific identity of ascaridoid nematodes from dogs and cats. Mol. Cell. Probes., 21(5-6): 349 – 354. DOI: 10.1016/j.mcp.2007.04.004

Li, M.W., Lin, R.Q., Song, H.Q., Wu, X.Y., Zhu, X.Q. (2008): The complete mitochondrial genomes for three Toxocara species of human and animal health significance. BMC Genomics. 9: 224 – 233. DOI: 10.1186/1471-2164-9-224

Macpherson, C.N.L. (2005): Human behaviour and the epidemiology of parasitic zoonoses. Int. J. Parasitol., 35(11-12): 1319 – 1331. DOI: 10.1016/j.ijpara.2005.06. 004

Macpherson, C.N.L. (2013): The epidemiology and public health importance of toxocariasis: A zoonosis of global importance. Int. J. Parasitol., 43(12-13): 999 – 1008. DOI: 10.1016/j.ijpara.2013.07.004

Nijse, R., Mughini-Gras, L., Wagenaar, J.A., Ploeger, H.W. (2014): Coprophagy in dogs interferes in the diagnosis of parasitic infections by faecal examination. Vet. Parasitol., 204(3-4): 304 – 309. DOI: 10.1016/j.vetpar.2014.05.019.

Oge, S., Oge, H. (2000): Prevalence of Toxocara spp. eggs in the soil of public parks in Ankara, Turkey. Dtsch. Tierarztl. Wochenschr., 107: 72 – 75.

Orhun, R., Ayaz, E. (2006): Prevalence of helminths in dogs in the region of Van and their potential public health significance. Türkiye Parazitol. Derg., 30(2): 103 – 107.

Overgaauw, P.A.M., Nederland, V. (1997): Aspects of Toxocara epidemiology: toxocarosis in the human. Crit. Rev. Microbiol., 23(3): 215 – 231. DOI: 10.3109/10408419709115137

Öge, S., Öge, H., Gönenç, B., Özbakiş, G., Aşti, C. (2013): Presence of Toxocara eggs on the hair of dogs and cats. Ankara Üniv. Vet. Fak. Derg., 60: 171 – 176

Öge, H., Öge, S., Özbakiş, G., Gürcan, S. (2014): Comparison of Toxocara eggs in hair and faecal samples from owned dogs and cats collected in Ankara, Turkey. Vet. Parasitol., 206 (3-4): 227 – 231. DOI: 10.1016/j.vetpar.2014.10.005

Öncel, T. (2004): Toxocariosis canis in domestic dogs in İstanbul, Turkey. Kafkas Üniv. Vet. Fak. Derg., 10(2): 151 – 153.

Özbakiş, G. (2015): PCR detection of Visceral Larvae Migrans in mice experimentally infected with Toxocara canis. PhD Thesis, Ankara, Turkey: The Graduate School of Health Sciences of Ankara University

Robertson, I.D., Thompson, R.C. (2002): Enteric parasitic zoonoses of domesticated dogs and cats. Microbes Infect., 4(8): 867 – 873. DOI: 10.1016/S1286-4579(02)01607-6

Roth, B., Schneider, C.C. (1971): Untersuchungen zur Abhangigkeiten des “weissen Blutbildes” bei Hauskatzen (Felis domestica) von Wurminfektionen des Darmes. [Relation of the white blood picture to intestinal helminth infestations in cats (Felis domestica)]. Berl. Munch. Tierarztl. Wochenschr., 84(22): 436 – 437 (In German)

Rubinsky-Elefant, G., Hirata, C.E., Yamamoto, H.J., Ferreira, M.U. (2010): Human toxocariasis: diagnosis, worldwide seroprevalences and clinical expression of the systemic and ocular form. Ann. Trop. Med. Parasitol., 104(1): 3 – 23. DOI: 10.1179/136485910X1 2607012373957.

Sager, H., Moret, C.H.S., Grimm, F., Deplazes, P., Doherr, M.G., Gottstein, B. (2006): Coprological study on intestinal helminths in Swiss dogs: temporal aspects of anthelminthic treatment. Parasitol. Res., 98(4): 333 – 338. DOI:

Saitou, N., Nei, M. (1987): The neighbor-joining method: A new method for reconstructing phylogenetic trees. Mol. Biol. Evol., 4: 406 – 425. DOI: 10.1093/oxfordjournals.molbev.a040454

Smith, H., Holland, C., Taylor, M., Magnaval, J.F., Schantz, P., Maizels, R. (2009): How common is human toxocariasis? Towards standardizing our knowledge. Trends Parasitol., 25(4): 182 – 188. DOI: 10.1016/

Soriano, S.V., Pierangeli, N.B., Roccia, I., Bergagna, H.F.J., Lazzarini, L.E., Celescinco, A., Saiz, M.S., Kossman, A., Contreras, P.A., Arias, C., Basualdo, J.A. (2010): A wide diversity of zoonotic intestinal parasites infects urban and rural dogs in Neuquen, Patagonia, Argentina. Vet. Parasitol., 167(1): 81 – 85. DOI: 10.1016/j. vetpar.2009.09.048

Sowemimo, O.A. (2007): Prevalence and intensity of Toxocara canis (Werner, 1782) in dogs and its potential public health significance in Ile-Ife, Nigeria. J. Helminthol., 81(4): 433 – 438. DOI: 10.1017/S0022149X07850267

Strube, C., Heuer, L., Janecek, E. (2013): Toxocara spp. infections in paratenic hosts. Vet. Parasitol., 193(4): 375 – 389. DOI: 10.1016/j.vetpar.2012.12.033

Szell, Z., Sreter-Lancz, Z., Sreter, T. (2014): Evaluation of faecal flotation methods followed by species-specific PCR for detection of Echinococcus multilocularis in the definitive hosts. Acta Parasitol., 59(2): 331 – 336. DOI: 10.2478/s11686-014-0248-9

Tamura, K., Stecher, G., Peterson, D., Filipski, A., Kumar, S. (2013): MEGA6: Molecular Evolutionary Genetics Analysis version 6.0. Mol. Biol. Evol., 30: 2725 – 2729. DOI: 10.1093/molbev/mst197

Truant, A.A., Elliot, S.H., Kelly, M.T., Smith, J.H. (1981): Comparison of formalin-ethyl ether sedimentation, formalin-ethyl acetate sedimentation, and zinc sulphate flotation techniques for detection of intestinal parasites. J. Clin. Microbiol., 13(5): 882 – 884

Ünlü, H., Eren, H. (2007): Gastro-intestinal helminths detected by fecal examination in stray dogs in the Aydin province. Türkiye Parazitol. Derg., 31(1): 46 – 50

Yildirim, A., İça, A., Düzlü, O., Yavuz, A., İnci, A. (2007): The prevalence of gastrointestinal helminths in dogs by coprological examination in Kayseri province. Erciyes Üniv. Vet. Fak. Derg., 4(2): 65 – 71

Wickramasinghe, S., Yatawara, L., Rajapakse, R.P.V.J., Agatsuma, T. (2009): Toxocara canis and Toxocara vitulorum: molecular characterization, discrimination, and phylogenetic analysis based on mitochondrial (ATP synthase subunit 6 and 12S) and nuclear ribosomal (ITS-2 and 28S) genes. Parasitol. Res., 104: 1425 – 1430. DOI: 10.1007/s00436-009-1345-9

Zhu, X.Q., Jacobs, D.E., Chilton, N.B., Sani, R.A., Cheng, N.A.B.Y., Gasser, R.B. (1998): Molecular characterization of a Toxocara variant from cats in Kuala Lumpur, Malaysia. Parasitology 117: 155 – 164

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